Map Overlapping

Hello all I am facing an issue when trying to navigate, i am following the Nox_project which uses gmapping while navigating, when i try to build a map using gmapping the map keeps getting Overlapped, i checked the odom by moving the robot in rviz 1 meter and in real life and rotating the robot on rviz and in real life and they matched so I don't thing its an odometry problem thats the only problem i am facing as when i try the navigation stack the robot planes a goal in a right way but the map keeps changing on it making it creating a new plan so could there be a problem in gmapping other than odometry for over lapping ?

Asked by Os7 on 2022-06-13 06:09:11 UTC

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Answers

You could try cartographer instead (or maybe hector slam). I'm about 85% sure I know what you mean (if you can, edit the post to add an image of your map).

Your odometry isn't perfect. Driving forward isn't too difficult. If you want a real test, drive around for about 3-4 minutes and then go back to your original point. Theoretically your odom and base_link should overlap again, once you're back at your starting point. You'll probably see that this isn't the case.

Gmapping doesn't deal well with this. Cartographer, on the other hand, creates a lot of small maps and tries to stitch them together (basically how the panorama function on your phone works).

Asked by Joe28965 on 2022-06-13 09:31:14 UTC

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I see, i have a motor which is faster than the other motor but not so much do you think that is what causing the issue ? Of course its a differential drive robot

Asked by Os7 on 2022-06-13 14:13:44 UTC

You mean that it's not driving in a straight line? In that case, it is definitely the problem.

Asked by Joe28965 on 2022-06-14 01:11:40 UTC

Yeah it drifts a small bit , will try to solve it and check again

Asked by Os7 on 2022-06-14 01:18:01 UTC

Then that will be the reason. Gmapping won't be able to deal with that.

Asked by Joe28965 on 2022-06-14 06:36:51 UTC

Hello , its me again :) i fixed the robot movement for the most part but used hector slam at the end which worked perfectly, however when i try to navigate the robot can go to some goals without problems but sometimes the laser sensor readings drifts away from the map make the goal totally different in the real map but the same goal in rviz any idea how to solve this or what is causing this

Asked by Os7 on 2022-06-19 06:40:25 UTC